package com.mdata.config;

import com.mdata.common.RedisKeyConstant;
import org.apache.commons.lang.StringUtils;
import org.apache.shiro.web.servlet.ShiroHttpServletRequest;
import org.apache.shiro.web.session.mgt.DefaultWebSessionManager;
import org.apache.shiro.web.util.WebUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;

import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import java.io.Serializable;

/**
 * 自定义session管理
 * <br/>
 * 传统结构项目中，shiro从cookie中读取sessionId以此来维持会话，在前后端分离的项目中（也可在移动APP项目使用），
 * 我们选择在ajax的请求头中传递sessionId，因此需要重写shiro获取sessionId的方式。
 * 自定义MySessionManager类继承DefaultWebSessionManager类，重写getSessionId方法
 * @author ：leigq
 * @date ：2019/7/1 10:52
 */
public class MySessionManager extends DefaultWebSessionManager {

    @Autowired
    private RedisTemplate redisTemplate;

    private static final String TOKEN = "token";

    private static final String REFERENCED_SESSION_ID_SOURCE = "Stateless request";

    @Override
    protected Serializable getSessionId(ServletRequest request, ServletResponse response) {
        String token = WebUtils.toHttp(request).getHeader(TOKEN);
        //如果请求头中有 Authorization 则其值为sessionId
        if (StringUtils.isNotEmpty(token) && redisTemplate.hasKey(RedisKeyConstant.SESSION_KEY_PREFIX + token)) {
            request.setAttribute(ShiroHttpServletRequest.REFERENCED_SESSION_ID_SOURCE, REFERENCED_SESSION_ID_SOURCE);
            request.setAttribute(ShiroHttpServletRequest.REFERENCED_SESSION_ID, token);
            request.setAttribute(ShiroHttpServletRequest.REFERENCED_SESSION_ID_IS_VALID, Boolean.TRUE);
            return token;
        } else {
            //否则按默认规则从cookie取sessionId
            return super.getSessionId(request, response);
        }
    }
}